0,2
There is a closed formula.
Z. C. Gao, V. A. Liskovets and N. C. Wormald, Enumeration of unrooted odd-valent regular planar maps
Cf. A112946.
Sequence in context: A207218 A185716 A084003 * A155843 A187527 A187698
Adjacent sequences: A118092 A118093 A118094 * A118096 A118097 A118098
nonn
Valery A. Liskovets (liskov(AT)im.bas-net.by), Apr 13 2006